Wood has always been and still remains the preferable construction material that provides for ecological cleanliness and comfort of the premises. However, wood has became less available at mass civil engineering because of its high cost that still does not allow to manage without the use of splint slabs, wooden fiber plywood and other products made with the use of binders based on formaldehyde containing resins. It is therefore desired to recycle the major part of the wood which is inevitably lost during the wood processing.
As it is known, the wood mechanical properties possess anisotropy, i.e. such wood properties like strength, wear resistance, elasticity etc. are dissimilar along and across the fibers. Moreover, the decorative features of the wood structure along the transversal and longitudinal cuts (wood cross-cut and wood rip-cut respectively) are also substantially different. These structure differences are associated with the fact that psychologically the human perception of a perfect object is based on its subconscious examination and comparison with the stereotype. From this stand point a surface unit of a wood cross-cut is esthetically advantageous since it is more attractive than that of a rip-cut and this fact enables using of small elements derived from the crosscut wood sections for creating a variety of decorative compositions which impart the final product attractive and natural appearance.
The above provides a basis for the novel approach to the issue of utilizing of wood off-cut wastes which is implemented by the present invention, i.e. utilizing of small off-cut units in the form of slices having certain diameter and height.
In accordance with the invention it is suggested to use such slices to form a face side of a composite wooden tile e.g. a splint-slab or decorative panel. Utilization of off-cut slices facilitates manufacturing of wooden tiles and allows producing of tiles with cery attractive decorative appearance.
The slices are prepared by sawing of the wood off-cuts (knots, substandard saw cuts etc.) to small slice units with equal heights. The slice units are assembled into a pattern to form a face layer of the article. For preparation of slices one can use not only commercial wood off-cuts but also fruit and decorative trees off-cuts. The use of wooden wastes resulting from the processing of various kinds of trees having different colors spectra and variety of the structure of their cross-section enables wide range of decorative combinations especially suitable for design of decorative wooden tiles.
The idea of using the structure of wooden cross-cuts for formation of the face side of a wooden tile has been conceived long time ago. The most explicit example of the use of wood cross-cuts (taking into account that wear resistance of the wood cross-cut is also better that that of the rip-cut) was the use of vertically fit logs in pavements in ancient Russian cities.
In the last decades the wood working industry has shown interest to the use of wood crosscut elements. In German patent DE2355925 there is disclosed the using of rectangular cross-cuts as a basis for the parquet floors. In Russian patent SU 1642957 it is disclosed the use of wooden slices to prepare a basis assembled from splint-slabs or other wood materials. The wooden inserts with equal diameter were glued to the slab's basis to form its face side. The assembled slab was polished and coated with a lacquer. The ready tiles having 500.times.500 mm size were used as parquet and as decorative panels. The disadvantage of this method is associated with the necessity in time consuming manual gluing of slices.
In Russian patent SU1761908 is disclosed a method of manufacturing of splint slabs in which the wood slices are laid to fit close to each other and the gaps between them is filled with a binder made of a resin based either on oligomers or polymers. The shortcoming of this method is associated with the fact that the bending strength of the ready article is strongly dependent on the binder strength. Furthermore, since the slabs are prepared from dissimilar materials the surface roughness of the ready slabs after polishing becomes heterogeneous and this deteriorates the esthetic appearance of the ready tile.
In Russian patent application 504901/15 of 1992 it is suggested to manufacture wooden boards assembled from butt end slices having two different diameters and of dedicated inserts which should be suitable for filling the free space between the adjacent slices. This method is time and labor consuming since it requires preparation of dedicated inserts, enlarging the space between the adjacent slices and manual placement of the inserts between the slices. Since this method employs only slices with particular diameter the utilization of wooden cross-cuts is limited. Furthermore, esthetically the articles prepared by this method are less attractive since the inserts situated between the large crosscut slices deteriorate the contiguity of their natural pattern.
Therefore it can be seen that despite the existence of various methods for manufacturing of composite wooden tiles from wood off-cut slices there is still felt a need for a new and improved manufacturing method which will sufficiently reduce or overcome the shortcomings of the prior art methods.